CN103926517B - The test device and method of power type LED thermal resistance - Google Patents

Abstract

Translated fromChinese

本发明公开了一种功率型LED的热阻测试装置，包括功率型LED、加热冷却单元、电源/测量单元、温度控制单元、光学参数测量单元和计算机；计算机用于控制电源/测量单元向功率型LED输出不同电流并测量对应的电功率；计算机通过控制温度控制单元控制加热冷却单元产生不同的温度值；光学参数测试单元用于采集功率型LED光学参数，并将该光学参数传输给计算机由计算机完成分析计算；电源/测量单元与加热冷却单元连接，用于配合计算机控制加热冷却单元产生不同的温度值。本发明采用一种新的测试功率型LED热阻方法，该方法通过获取效率‑结温系数k_e，热功率与电功率转换系数k_h，以及LED外部散热器热阻R_hs来得到LED的热阻值，降低了测试成本，操作简单。

The invention discloses a thermal resistance testing device of a power type LED, which comprises a power type LED, a heating and cooling unit, a power supply/measurement unit, a temperature control unit, an optical parameter measurement unit and a computer; the computer is used to control the power supply/measurement unit to the power Type LED outputs different currents and measures the corresponding electric power; the computer controls the heating and cooling unit to generate different temperature values by controlling the temperature control unit; the optical parameter test unit is used to collect the optical parameters of the power type LED, and transmit the optical parameters to the computer by the computer The analysis calculation is completed; the power supply/measurement unit is connected with the heating and cooling unit, which is used to cooperate with the computer to control the heating and cooling unit to generate different temperature values. The present invention adopts a new method for testing power-type LED thermal resistance. The method obtains the thermal resistance of the LED by obtaining the efficiency-junction temperature coefficient k_e , the conversion coefficient of thermal power and electric power k_h , and the thermal resistance R_hs of the external heat sink of the LED. The resistance value reduces the test cost and is easy to operate.

Description

Translated fromChinese

功率型LED热阻的测试装置及方法Test device and method for thermal resistance of power LED

技术领域technical field

本发明属于光电测试技术领域，具体涉及一种测试功率型LED热阻的测试方法。The invention belongs to the technical field of photoelectric testing, and in particular relates to a testing method for testing thermal resistance of power LEDs.

背景技术Background technique

功率型LED是半导体照明领域的核心器件，然而在LED正常工作中，有70％以上的电能转化为热能，使得LED芯片结温显著升高，严重影响LED的光电性能，造成光输出衰减、寿命减少、可靠性降低等。因此需要对功率型LED热阻等热特性参数进行准确快速的测试，为LED封装和热沉设计提供设计参数并进行有效的热管理。Power LED is the core device in the field of semiconductor lighting. However, in the normal operation of the LED, more than 70% of the electric energy is converted into heat energy, which makes the junction temperature of the LED chip rise significantly, which seriously affects the photoelectric performance of the LED, resulting in attenuation of light output and long life. reduction, reduced reliability, etc. Therefore, it is necessary to accurately and quickly test thermal characteristic parameters such as thermal resistance of power LEDs, provide design parameters for LED packaging and heat sink design, and perform effective thermal management.

目前国内外测量LED热学特性的方法主要有红外热成像法、光谱法、光功率法、管脚温度法和电学参数法。电学参数法是基于LED两端正向压降与结温呈线性关系，通过快速切换测量电流与加热电流时测量端电压的变化得到结温，进一步计算得到LED热阻。该方法不需要破坏LED封装结构，且测量精度高、速度快，是目前国际上通用的标准方法。但主要缺点是电流转换过程中热量损失造成热阻测试误差较大，另外检测PN结上正向电压的变化需要非常高精度的数据采集仪器，难以降低研发成本。At present, the methods for measuring the thermal characteristics of LEDs at home and abroad mainly include infrared thermal imaging, spectroscopy, optical power method, pin temperature method and electrical parameter method. The electrical parameter method is based on the linear relationship between the forward voltage drop at both ends of the LED and the junction temperature. The junction temperature is obtained by quickly switching the measurement current and the heating current when the measurement terminal voltage changes, and the thermal resistance of the LED is further calculated. This method does not need to destroy the LED packaging structure, and has high measurement accuracy and fast speed, and is currently a standard method commonly used in the world. However, the main disadvantage is that the heat loss during the current conversion process causes large errors in the thermal resistance test. In addition, detecting the change of the forward voltage on the PN junction requires a very high-precision data acquisition instrument, which makes it difficult to reduce the cost of research and development.

发明内容Contents of the invention

鉴于此，本发明的目的是提供一种新的测试功率型LED热阻的方法及装置，采用该方法和装置能有效降低功率型LED热阻测试的系统成本，且操作简单，具有一定的工程应用价值。In view of this, the purpose of the present invention is to provide a new method and device for testing power-type LED thermal resistance, which can effectively reduce the system cost of power-type LED thermal resistance testing, and is simple to operate and has certain engineering advantages. Value.

本发明的目的之一是通过这样的技术方案实现的，功率型LED的热阻测试装置，包括功率型LED、加热冷却单元、电源/测量单元、温度控制单元、光学参数测量单元和计算机；One of the objectives of the present invention is achieved by such a technical solution, the thermal resistance testing device of a power type LED includes a power type LED, a heating and cooling unit, a power supply/measurement unit, a temperature control unit, an optical parameter measurement unit and a computer;

所述计算机用于控制电源/测量单元向功率型LED输出不同的电流并测量对应的电功率；The computer is used to control the power supply/measurement unit to output different currents to the power LED and measure the corresponding electric power;

所述计算机通过控制温度控制单元控制加热冷却单元产生不同的温度值；The computer controls the heating and cooling unit to generate different temperature values by controlling the temperature control unit;

所述光学参数测试单元用于采集功率型LED的光学参数，并将该光学参数传输给计算机由计算机完成分析计算；The optical parameter testing unit is used to collect the optical parameters of the power LED, and transmit the optical parameters to the computer to complete the analysis and calculation by the computer;

所述电源/测量单元与加热冷却单元连接，用于配合计算机控制加热冷却单元产生不同的温度值。The power supply/measurement unit is connected with the heating and cooling unit, and is used to cooperate with the computer to control the heating and cooling unit to generate different temperature values.

进一步，所述加热冷却单元包括依次连接的热沉、半导体热电制冷片和散热器；所述功率型LED设置在热沉上，所述半导体热电制冷片与温度控制单元连接。Further, the heating and cooling unit includes a heat sink, a semiconductor thermoelectric cooling chip and a radiator connected in sequence; the power LED is arranged on the heat sink, and the semiconductor thermoelectric cooling chip is connected to a temperature control unit.

进一步，所述光学参数测试单元为集光型参数测试单元，所述集光型光学参数测试单元包括集光装置和光探装置，所述功率型LED设置在集光装置的入光口处，所述光探测装置设置在集光装置的收光口处；所述集光装置为积分球，所述光探测装置为光度探头或辐射探头。Further, the optical parameter testing unit is a light-collecting type parameter testing unit, the light-collecting type optical parameter testing unit includes a light-collecting device and a light-detecting device, and the power-type LED is arranged at the light entrance of the light-collecting device, so The light detection device is arranged at the light receiving port of the light collection device; the light collection device is an integrating sphere, and the light detection device is a photometric probe or a radiation probe.

进一步，所述光学参数测试单元为非集光型参数测试单元，所述非集光型参数测试单元包括光探测装置，所述光探测装置设置在功率型LED光轴上；所述光探测装置为光度探头或辐射探头。Further, the optical parameter testing unit is a non-light-collecting parameter testing unit, and the non-light-collecting parameter testing unit includes a light detection device, and the light detection device is arranged on the optical axis of the power LED; the light detection device It is a photometric probe or a radiation probe.

功率型LED的热阻测试方法，测量功率型LED光学参数对电功率变化关系，其中光学参数为总光通量、部分光通量、光照度、光功率、轴向光功率、轴向光照度、相对辐射强度等参数中的任何一个，并对光学参数-电功率曲线进行最小二乘非线性拟合，得到光学参数极值处的电功率；功率型LED热阻与极值处电功率的函数关系式为式(1)，进一步得到k_e、k_h和R_hs三个参数的值，即可得到功率型LED热阻R_jc；The thermal resistance test method of power LEDs, measuring the relationship between the optical parameters of power LEDs and the change of electric power, where the optical parameters are total luminous flux, partial luminous flux, illuminance, optical power, axial optical power, axial illuminance, relative radiation intensity and other parameters Any one of the optical parameter-electric power curves is fitted by least squares nonlinear fitting to obtain the electric power at the extreme value of the optical parameter; the functional relationship between the thermal resistance of the power LED and the electric power at the extreme value is formula (1), and further Get the values of the three parameters k_e , k_h and R_hs , then you can get the power LED thermal resistance R_jc ;

${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>jc</span>jc</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>max</span>max</span>}}}<span><span>-</span>-</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>hs</span>hs</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式(1)中，P_dmax为光学参数极值时对应的电功率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻且已知。In formula (1), P_dmax is the electric power corresponding to the extreme value of optical parameters, k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of power LED, R_hs is the thermal resistance of the LED's external heat sink and is known.

进一步，获得P_dmax的方法包括以下子步骤：Further, the method for obtaining P_dmax includes the following substeps:

S61：计算机控制电源/测量单元向功率型LED输出不同的电流，利用电源/测量单元测得不同注入电流下电功率P_d；同时利用光学参数测量单元测得光学参数P_O，得到两者之间的关系曲线P_O-P_d；S61: The computer controls the power supply/measurement unit to output different currents to the power LED, and uses the power supply/measurement unit to measure the electric power P_d under different injection currents; at the same time, uses the optical parameter measurement unit to measure the optical parameter P_O , and obtains the difference between the two The relationship curve P_O -P_d ;

S62：光学参数P_O与电功率P_d符合式(2)关系：S62: The relationship between the optical parameter P_O and the electric power P_d conforms to formula (2):

P_O＝E_p0[P_d+k_ek_h(R_jc+R_hs)P_d²] (2)P_O ＝E_p0 [P_d +k_e k_h (R_jc +R_hs )P_d² ] (2)

当光学参数P_O极值时，电功率P_dmax可表述为式(3)：When the optical parameter P_O is at the extreme value, the electric power P_dmax can be expressed as formula (3):

${\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>max</span>max</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>jc</span>jc</span>}}<span><span>+</span>+</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>hs</span>hs</span>}}<span><span>)</span>)</span>}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>3</span>3</span>}<span><span>)</span>)</span>$

其中E_p0为环境温度为T₀时的光参数-电功率效率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻；Where E_p0 is the optical parameter-electric power efficiency when the ambient temperature is T₀ , k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of the power LED, and R_hs is The thermal resistance of the LED external heat sink;

S63：根据式(2)，对P_O-P_d关系曲线进行最小二乘非线性拟合，得到光学参数极值处的电功率P_dmax。S63: According to the formula (2), the least square nonlinear fitting is performed on the P_O -P_d relationship curve to obtain the electric power P_dmax at the extreme value of the optical parameter.

进一步，获得k_h的方法包括以下子步骤：Further, the method for obtaining_kh includes the following sub-steps:

S71：计算机控制电源/测量单元向功率型LED输出额定工作电流，利用电源/测量单元测得额定电流下电功率P_d；利用光学参数测量单元测得光功率P_L，利用公式(4)得到热功率与电功率的转换系数k_h；S71: The computer controls the power supply/measurement unit to output the rated operating current to the power LED, and uses the power supply/measurement unit to measure the electrical power P_d under the rated current; uses the optical parameter measurement unit to measure the optical power_PL , and uses the formula (4) to obtain the thermal power The conversion coefficient k_h of power and electric power;

${\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}}<span><span>-</span>-</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>L</span>L</span>}}}{{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}<span><span>)</span>)</span>$

进一步，获取k_e的方法包括以下子步骤：Further, the method for obtaining k_e includes the following sub-steps:

S81：计算机控制电源/测量单元向功率型LED输出合适的工作电流，使得LED能点亮但是不产生明显的热效应；利用温度控制单元控制加热冷却单元产生不同的温度值；利用电源/测量单元测量不同温度下电功率P_d；同时利用光学参数测量单元测得光学参数值P_O，计算得到光参数-电功率效率E与结温T_j的关系曲线E-T_j；S81: The computer controls the power supply/measurement unit to output a suitable working current to the power LED, so that the LED can light up but does not produce obvious thermal effects; use the temperature control unit to control the heating and cooling unit to produce different temperature values; use the power supply/measurement unit to measure The electric power P_d at different temperatures; at the same time, the optical parameter value P_O is measured by the optical parameter measurement unit, and the relationship curve ET_j of the optical parameter-electric power efficiency E and the junction temperature T_j is calculated;

S82：采用最小二乘原理对E-T_j曲线数据进行线性拟合，得到效率与结温的系数值k_e；S82: Using the least square principle to linearly fit the ET_j curve data to obtain the coefficient value k_e of efficiency and junction temperature;

E＝E_p0[1+k_e(T_j-T₀)] (5)E＝E_p0 [1+k_e (T_j -T₀ )] (5)

其中E为光参数-电功率效率，E_p0为环境温度为T₀时的光参数-电功率效率。Among them, E is the optical parameter-electric power efficiency, and E_p0 is the optical parameter-electric power efficiency when the ambient temperature is T₀ .

由于采用了上述技术方案，本发明具有如下的优点:Owing to adopted above-mentioned technical scheme, the present invention has following advantage:

1、运用常规的测量数据进行分析，方法简单且可操作性强，数据结果可信度高。1. Using conventional measurement data for analysis, the method is simple and operable, and the data results are highly reliable.

2、不需要高精度的专门的数据采集仪器，只需要常规的光电测量设备，因此所需测试成本低，非常适合于企业的工程应用。2. It does not require high-precision special data acquisition instruments, but only conventional photoelectric measurement equipment, so the required test cost is low, and it is very suitable for enterprise engineering applications.

附图说明Description of drawings

为了使本发明的目的、技术方案和优点更加清楚，下面将结合附图对本发明作进一步的详细描述，其中：In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with the accompanying drawings, wherein:

图1为测试装置原理框图；Fig. 1 is a schematic block diagram of the testing device;

图2为光通量-电功率以及光效-结温测试原理图；Figure 2 is a schematic diagram of the luminous flux-electric power and luminous efficiency-junction temperature test;

图3为光通量随电功率变化曲线以及拟合曲线图；Fig. 3 is a curve of luminous flux changing with electric power and a fitting curve;

图4为光效与结温变化曲线以及拟合曲线图；Figure 4 is the light efficiency and junction temperature change curve and fitting curve;

其中，1、功率型LED；2、热沉；3、半导体热电制冷片；4、散热器；5、加热冷却单元；6、电源/测量单元；7、温度控制单元；8、积分球；9、光度探头或者辐射探头；10、光学参数测量单元；11、计算机。Among them, 1. Power LED; 2. Heat sink; 3. Semiconductor thermoelectric cooling sheet; 4. Radiator; 5. Heating and cooling unit; 6. Power supply/measurement unit; 7. Temperature control unit; 8. Integrating sphere; 9 1. Photometric probe or radiation probe; 10. Optical parameter measurement unit; 11. Computer.

具体实施方式detailed description

以下将结合附图，对本发明的优选实施例进行详细的描述；应当理解，优选实施例仅为了说明本发明，而不是为了限制本发明的保护范围。The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings; it should be understood that the preferred embodiments are only for illustrating the present invention, rather than limiting the protection scope of the present invention.

如图1、2所示，功率型LED的热阻测试装置，包括功率型LED1、加热冷却单元5、电源/测量单元6、温度控制单元7、光学参数测量单元10和计算机11；As shown in Figures 1 and 2, the thermal resistance testing device of a power type LED includes a power type LED1, a heating and cooling unit 5, a power supply/measurement unit 6, a temperature control unit 7, an optical parameter measurement unit 10 and a computer 11;

所述计算机用于控制电源/测量单元向功率型LED输出不同的电流并测量对应的电功率；The computer is used to control the power supply/measurement unit to output different currents to the power LED and measure the corresponding electric power;

所述计算机通过控制温度控制单元控制加热冷却单元产生不同的温度值；The computer controls the heating and cooling unit to generate different temperature values by controlling the temperature control unit;

所述光学参数测试单元用于采集功率型LED的光学参数，并将该光学参数传输给计算机由计算机完成分析计算；其中光学参数包括总光通量、部分光通量、光照度、光功率、轴向光功率、轴向光照度、相对辐射强度等，在本实施例中光学参数测试单元10用于采集功率型LED的总光通量。The optical parameter testing unit is used to collect the optical parameters of the power LED, and transmit the optical parameters to the computer to complete the analysis and calculation by the computer; wherein the optical parameters include total luminous flux, partial luminous flux, illuminance, optical power, axial optical power, Axial illuminance, relative radiation intensity, etc., in this embodiment, the optical parameter testing unit 10 is used to collect the total luminous flux of the power LED.

所述电源/测量单元与加热冷却单元连接，用于配合计算机控制加热冷却单元产生不同的温度值。The power supply/measurement unit is connected with the heating and cooling unit, and is used to cooperate with the computer to control the heating and cooling unit to generate different temperature values.

所述加热冷却单元包括依次连接的热沉2、半导体热电制冷片3和散热器4；所述功率型LED1设置在热沉上，所述半导体热电制冷片与温度控制单元连接。The heating and cooling unit includes a heat sink 2, a semiconductor thermoelectric cooling chip 3 and a radiator 4 connected in sequence; the power LED 1 is arranged on the heat sink, and the semiconductor thermoelectric cooling chip is connected to a temperature control unit.

本实施例中光参数测试单元为集光型参数测试单元，本实施例中，采用积分球8作为集光装置，采用光度探头9(或辐射探头)作为光探装置，功率型LED设置在积分球的入光口处，光度探头(或辐射探头)设置在积分球的收光口处。In this embodiment, the optical parameter testing unit is a light-collecting type parameter testing unit. In this embodiment, the integrating sphere 8 is used as the light-collecting device, the photometric probe 9 (or radiation probe) is used as the light detecting device, and the power type LED is arranged on the integrating sphere. At the light entrance of the sphere, the photometric probe (or radiation probe) is set at the light receiving port of the integrating sphere.

当然采用非集光型光学参数测试单元也能实现对功率型LED光学参数的采集，当采集非集光型光学参数测试的时候，只需将光度探头9(或辐射探头)设置在功率型LED光轴上。Of course, the collection of optical parameters of power LEDs can also be realized by using a non-light-collecting optical parameter test unit. on the optical axis.

使用上述测试装置进行功率型LED热阻进行测试的方法，测量功率型LED光学参数对电功率变化关系，光学参数P_O选取为总光通量Φ_v，并对总光通量-电功率曲线进行最小二乘非线性拟合，得到总光通量极值处的电功率。功率型LED热阻与极值处电功率的函数关系式为式(1)，进一步得到k_e、k_h和R_hs三个参数的值，即可得到功率型LED热阻R_jc；Using the above test device to test the thermal resistance of power LEDs, measure the relationship between the optical parameters of power LEDs and the change of electric power, the optical parameter P_O is selected as the total luminous flux Φ_v , and the least square nonlinearity is performed on the total luminous flux-electric power curve Fitting, the electric power at the extreme value of the total luminous flux is obtained. The functional relationship between the power LED thermal resistance and the electric power at the extreme value is formula (1), and the values of the three parameters k_e , k_h and R_hs can be further obtained to obtain the power LED thermal resistance R_jc ;

${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>jc</span>jc</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>max</span>max</span>}}}<span><span>-</span>-</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>hs</span>hs</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$

式(1)中，P_dmax为光学参数极值时对应的电功率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻且已知。In formula (1), P_dmax is the electric power corresponding to the extreme value of optical parameters, k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of power LED, R_hs is the thermal resistance of the LED's external heat sink and is known.

获得P_dmax的方法包括以下子步骤：The method for obtaining P_dmax includes the following sub-steps:

计算机11控制电源/测量单元(SMU)6向功率型LED输出不同的电流，利用SMU测得不同注入电流下电功率P_d；同时利用光学参数测量单元测得总光通量Φ_v，得到两者之间的关系曲线Φ_v-P_d。The computer 11 controls the power supply/measurement unit (SMU) 6 to output different currents to the power LED, and uses the SMU to measure the electric power P_d under different injection currents; at the same time, the optical parameter measurement unit is used to measure the total luminous flux Φ_v , and the relationship between the two is obtained. The relationship curve Φ_v -P_d .

光通量Φ_v与电功率P_d满足式(2)函数关系。The luminous flux Φ_v and the electric power P_d satisfy the functional relationship of formula (2).

Φ_v＝E_p0[P_d+k_ek_h(R_jc+R_hs)P_d²] (2)Φ_v ＝E_p0 [P_d +k_e k_h (R_jc +R_hs )P_d² ] (2)

当总光通量Φ_v极值时，电功率P_dmax可表述为式(3)。When the total luminous flux Φ_v extreme value, the electric power P_dmax can be expressed as formula (3).

${\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>max</span>max</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>jc</span>jc</span>}}<span><span>+</span>+</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>hs</span>hs</span>}}<span><span>)</span>)</span>}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>3</span>3</span>}<span><span>)</span>)</span>$

其中E_p0为环境温度为T₀时的总光通量-电功率效率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻。Where E_p0 is the total luminous flux-electric power efficiency when the ambient temperature is T₀ , k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of the power LED, and R_hs is The thermal resistance of the LED's external heat sink.

根据式(2)，对Φ_v-P_d关系曲线进行最小二乘非线性拟合，得到总光通量极值处的电功率P_dmax，其光通量随电功率变化曲线如图3所示。According to formula (2), the least squares nonlinear fitting is performed on the Φ_v -P_d relationship curve, and the electric power P_dmax at the extreme value of the total luminous flux is obtained. The change curve of luminous flux with electric power is shown in Figure 3.

获得k_h的方法包括以下子步骤：The method for obtaining k_h includes the following sub-steps:

计算机11控制电源/测量单元(SMU)6向功率型LED输出额定工作电流，利用SMU测得额定电流下电功率P_d；将光度探头替换为辐射探头，测得光功率P_L，利用公式(4)得到热功率与电功率的转换系数k_h。The computer 11 controls the power supply/measurement unit (SMU) 6 to output the rated operating current to the power LED, and uses the SMU to measure the electrical power P_d under the rated current; replace the photometric probe with a radiation probe, and measure the optical power P_L , using the formula (4 ) to obtain the conversion coefficient k_h of thermal power and electric power.

${\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}}<span><span>-</span>-</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>L</span>L</span>}}}{{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}<span><span>)</span>)</span>$

获取k_e的方法包括以下子步骤：The method for obtaining k_e includes the following sub-steps:

计算机11控制电源/测量单元(SMU)6向功率型LED输出5mA工作电流。利用温度控制单元7控制加热冷却单元5产生40℃、50℃、60℃、70℃、80℃等不同温度值。利用SMU测量不同温度下电功率P_d；同时利用光学参数测量单元测得总光通量Φ_v，计算得到总光通量Φ_v-电功率效率E(总光通量/电功率)与结温T_j的关系曲线E-T_j。The computer 11 controls the power supply/measurement unit (SMU) 6 to output 5mA working current to the power LED. The heating and cooling unit 5 is controlled by the temperature control unit 7 to generate different temperature values such as 40°C, 50°C, 60°C, 70°C, and 80°C. Use the SMU to measure the electric power P_d at different temperatures; at the same time, use the optical parameter measurement unit to measure the total luminous flux Φ_v , and calculate the relationship curve ET_j of the total luminous flux Φ_v - electric power efficiency E (total luminous flux/electric power) and junction temperature T_j .

采用最小二乘原理对E-T_j曲线数据进行线性拟合，得到效率与结温的系数值k_e。The least square principle is used to linearly fit the ET_j curve data, and the coefficient value k_e of efficiency and junction temperature is obtained.

E＝E_p0[1+k_e(T_j-T₀)] (5)E＝E_p0 [1+k_e (T_j -T₀ )] (5)

其光效与结温变化曲线如图4所示。The light efficiency and junction temperature change curve is shown in Figure 4.

利用式(3)得到功率型LED热阻为式(6)，将R_hs、k_h、k_e代入，可计算得到热阻值。本例中，测得的功率型LED热阻值为9.2(℃/W)，标称热阻值为8(℃/W)。Using formula (3) to get the thermal resistance of the power LED is formula (6), and substituting R_hs , k_h , k_e , the thermal resistance value can be calculated. In this example, the measured thermal resistance value of the power LED is 9.2 (°C/W), and the nominal thermal resistance value is 8 (°C/W).

${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>jc</span>jc</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>max</span>max</span>}}}<span><span>-</span>-</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>hs</span>hs</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>6</span>6</span>}<span><span>)</span>)</span>$

本发明采用一种新的测试功率型LED热阻的方法，该方法通过获取效率-结温系数k_e，热功率与电功率的转换系数k_h，以及为LED外部散热器的热阻R_hs来得到功率型LED的热阻值，降低了测试系统成本，且操作简单，具有一定的工程应用价值。The present invention adopts a new method for testing the thermal resistance of power-type LEDs. The method obtains the efficiency-junction temperature coefficient k_e , the conversion coefficient k_h of thermal power and electric power, and the thermal resistance R_hs of the external heat sink of the LED. Obtaining the thermal resistance value of the power LED reduces the cost of the test system, and is easy to operate, which has certain engineering application value.

以上所述仅为本发明的优选实施例，并不用于限制本发明，显然，本领域的技术人员可以对本发明进行各种改动和变型而不脱离本发明的精神和范围。这样，倘若本发明的这些修改和变型属于本发明权利要求及其等同技术的范围之内，则本发明也意图包含这些改动和变型在内。The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and equivalent technologies thereof, the present invention also intends to include these modifications and variations.

Claims (8)

Translated fromChinese

1.一种功率型LED的热阻测试装置，其特征在于：包括功率型LED、加热冷却单元、电源/测量单元、温度控制单元、光学参数测试单元和计算机；1. A thermal resistance testing device of a power type LED, characterized in that: comprising a power type LED, a heating and cooling unit, a power supply/measurement unit, a temperature control unit, an optical parameter testing unit and a computer;所述计算机用于控制电源/测量单元向功率型LED输出不同的电流并测量对应的电功率；The computer is used to control the power supply/measurement unit to output different currents to the power LED and measure the corresponding electric power;所述计算机通过控制温度控制单元控制加热冷却单元产生不同的温度值；The computer controls the heating and cooling unit to generate different temperature values by controlling the temperature control unit;所述光学参数测试单元用于采集功率型LED的光学参数，并将该光学参数传输给计算机由计算机完成分析计算，The optical parameter testing unit is used to collect the optical parameters of the power LED, and transmit the optical parameters to the computer to complete the analysis and calculation by the computer,计算机测量功率型LED光学参数对电功率变化关系，其中光学参数为总光通量、部分光通量、光照度、光功率、轴向光功率、轴向光照度、相对辐射强度参数中的任何一个，并对光学参数-电功率曲线进行最小二乘非线性拟合，得到光学参数极值处的电功率；功率型LED热阻与极值处电功率的函数关系式为式(1)，进一步得到k_e、k_h和R_hs三个参数的值，即可得到功率型LED热阻R_jc；The computer measures the relationship between the optical parameters of the power type LED and the electric power, wherein the optical parameters are any one of the total luminous flux, partial luminous flux, illuminance, optical power, axial optical power, axial illuminance, and relative radiation intensity parameters, and the optical parameters- The electrical power curve is fitted by least squares nonlinearity to obtain the electrical power at the extreme value of the optical parameters; the functional relationship between the thermal resistance of the power LED and the electrical power at the extreme value is formula (1), and k_e , k_h and R_hs are further obtained The values of the three parameters can be used to obtain the thermal resistance R_jc of the power LED;${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>j</span>j</span>}\mathrm{<span><span>c</span>c</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>m</span>m</span>}\mathrm{<span><span>a</span>a</span>}\mathrm{<span><span>x</span>x</span>}}}<span><span>-</span>-</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>h</span>h</span>}\mathrm{<span><span>s</span>the\; s</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$式(1)中，P_dmax为光学参数极值时对应的电功率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻且已知；In formula (1), P_dmax is the electric power corresponding to the extreme value of optical parameters, k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of power LED, R_hs is the thermal resistance of the LED external heat sink and is known;所述电源/测量单元与加热冷却单元连接，用于配合计算机控制加热冷却单元产生不同的温度值。The power supply/measurement unit is connected with the heating and cooling unit, and is used to cooperate with the computer to control the heating and cooling unit to generate different temperature values.2.根据权利要求1所述的功率型LED的热阻测试装置，其特征在于：所述加热冷却单元包括依次连接的热沉、半导体热电制冷片和散热器；所述功率型LED设置在热沉上，所述半导体热电制冷片与温度控制单元连接。2. The thermal resistance testing device of power LED according to claim 1, characterized in that: the heating and cooling unit includes a heat sink, a semiconductor thermoelectric cooling chip and a radiator connected in sequence; On top of that, the semiconductor thermoelectric cooling sheet is connected with the temperature control unit.3.根据权利要求1所述的功率型LED的热阻测试装置，其特征在于：所述光学参数测试单元为集光型参数测试单元，所述集光型参数测试单元包括集光装置和光探测装置，所述功率型LED设置在集光装置的入光口处，所述光探测装置设置在集光装置的收光口处；所述集光装置为积分球，所述光探测装置为光度探头或辐射探头。3. The thermal resistance testing device of power LED according to claim 1, characterized in that: the optical parameter testing unit is a light-collecting type parameter testing unit, and the light-collecting type parameter testing unit includes a light-collecting device and a light detector device, the power type LED is set at the light entrance of the light collection device, and the light detection device is set at the light collection port of the light collection device; the light collection device is an integrating sphere, and the light detection device is a photometric probe or radiation probe.4.根据权利要求1所述的功率型LED的热阻测试装置，其特征在于：所述光学参数测试单元为非集光型参数测试单元，所述非集光型参数测试单元包括光探测装置，所述光探测装置设置在功率型LED光轴上；所述光探测装置为光度探头或辐射探头。4. The thermal resistance test device of power LED according to claim 1, characterized in that: the optical parameter test unit is a non-light collection type parameter test unit, and the non-light collection type parameter test unit includes a light detection device , the light detection device is arranged on the optical axis of the power LED; the light detection device is a photometric probe or a radiation probe.5.一种功率型LED的热阻测试方法，其特征在于：测量功率型LED光学参数对电功率变化关系，其中光学参数为总光通量、部分光通量、光照度、光功率、轴向光功率、轴向光照度、相对辐射强度参数中的任何一个，并对光学参数-电功率曲线进行最小二乘非线性拟合，得到光学参数极值处的电功率；功率型LED热阻与极值处电功率的函数关系式为式(1)，进一步得到k_e、k_h和R_hs三个参数的值，即可得到功率型LED热阻R_jc；5. A thermal resistance testing method of power type LED, it is characterized in that: measure power type LED optical parameter to electric power change relation, wherein optical parameter is total luminous flux, partial luminous flux, illuminance, optical power, axial optical power, axial Any one of the illuminance and relative radiation intensity parameters, and perform least square nonlinear fitting on the optical parameter-electric power curve to obtain the electric power at the extreme value of the optical parameter; the functional relationship between the thermal resistance of the power LED and the electric power at the extreme value According to formula (1), the values of the three parameters k_e , k_h and R_hs can be further obtained, and then the thermal resistance R_jc of the power LED can be obtained;${\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>j</span>j</span>}\mathrm{<span><span>c</span>c</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>m</span>m</span>}\mathrm{<span><span>a</span>a</span>}\mathrm{<span><span>x</span>x</span>}}}<span><span>-</span>-</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>h</span>h</span>}\mathrm{<span><span>s</span>the\; s</span>}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>1</span>1</span>}<span><span>)</span>)</span>$式(1)中，P_dmax为光学参数极值时对应的电功率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻且已知。In formula (1), P_dmax is the electric power corresponding to the extreme value of optical parameters, k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of power LED, R_hs is the thermal resistance of the LED's external heat sink and is known.6.根据权利要求5所述的功率型LED的热阻测试方法，其特征在于：获得P_dmax的方法包括以下子步骤：6. The thermal resistance testing method of power type LED according to claim 5, is characterized in that: the method for obtaining P_dmax comprises the following sub-steps:S61：计算机控制电源/测量单元向功率型LED输出不同的电流，利用电源/测量单元测得不同注入电流下电功率P_d；同时利用光学参数测试单元测得光学参数P_O，得到两者之间的关系曲线P_O-P_d；S61: The computer controls the power supply/measurement unit to output different currents to the power LED, and uses the power supply/measurement unit to measure the electric power P_d under different injection currents; at the same time, uses the optical parameter test unit to measure the optical parameter P_O , and obtains the difference between the two The relationship curve P_O -P_d ;S62：光学参数P_O与电功率P_d符合式(2)关系：S62: The relationship between the optical parameter P_O and the electric power P_d conforms to formula (2):P_O＝E_p0[P_d+k_ek_h(R_jc+R_hs)P_d²] (2)P_O ＝E_p0 [P_d +k_e k_h (R_jc +R_hs )P_d² ] (2)当光学参数P_O极值时，电功率P_dmax可表述为式(3)：When the optical parameter P_O is at the extreme value, the electric power P_dmax can be expressed as formula (3):${\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}\mathrm{<span><span>max</span>max</span>}}<span><span>=</span>=</span><span><span>-</span>-</span>\frac{\mathrm{<span><span>1</span>1</span>}}{\mathrm{<span><span>2</span>2</span>}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>e</span>e</span>}}{\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}<span><span>(</span>(</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>j</span>j</span>}\mathrm{<span><span>c</span>c</span>}}<span><span>+</span>+</span>{\mathrm{<span><span>R</span>R</span>}}_{\mathrm{<span><span>h</span>h</span>}\mathrm{<span><span>s</span>the\; s</span>}}<span><span>)</span>)</span>}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>3</span>3</span>}<span><span>)</span>)</span>$其中E_p0为环境温度为T₀时的光参数-电功率效率，k_e为效率-结温系数，k_h为热功率与电功率的转换系数，R_jc为功率型LED的热阻，R_hs为LED外部散热器的热阻；Where E_p0 is the optical parameter-electric power efficiency when the ambient temperature is T₀ , k_e is the efficiency-junction temperature coefficient, k_h is the conversion coefficient between thermal power and electric power, R_jc is the thermal resistance of the power LED, and R_hs is The thermal resistance of the LED external heat sink;S63：根据式(2)，对P_O-P_d关系曲线进行最小二乘非线性拟合，得到光学参数极值处的电功率P_dmax。S63: According to the formula (2), the least square nonlinear fitting is performed on the P_O -P_d relationship curve to obtain the electric power P_dmax at the extreme value of the optical parameter.7.根据权利要求6所述的功率型LED的热阻测试方法，其特征在于：获得k_h的方法包括以下子步骤：7. The thermal resistance testing method of power type LED according to claim 6 is characterized in that: the method for obtaining_kh comprises the following sub-steps:S71：计算机控制电源/测量单元向功率型LED输出额定工作电流，利用电源/测量单元测得额定电流下电功率P_d；利用光学参数测试单元测得光功率P_L，利用公式(4)得到热功率与电功率的转换系数k_h；S71: The computer controls the power supply/measurement unit to output the rated operating current to the power LED, and uses the power supply/measurement unit to measure the electrical power P_d under the rated current; uses the optical parameter test unit to measure the optical power_PL , and uses the formula (4) to obtain the thermal power The conversion coefficient k_h of power and electric power;${\mathrm{<span><span>k</span>k</span>}}_{\mathrm{<span><span>h</span>h</span>}}<span><span>=</span>=</span>\frac{{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}}<span><span>-</span>-</span>{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>L</span>L</span>}}}{{\mathrm{<span><span>P</span>P</span>}}_{\mathrm{<span><span>d</span>d</span>}}}<span><span>-</span>-</span><span><span>-</span>-</span><span><span>-</span>-</span><span><span>(</span>(</span>\mathrm{<span><span>4</span>4</span>}<span><span>)</span>)</span><span><span>.</span>.</span>$8.根据权利要求6所述的功率型LED的热阻测试方法，其特征在于：获取k_e的方法包括以下子步骤：8. The thermal resistance testing method of power type LED according to claim 6, is characterized in that: the method for obtaining_ke comprises the following substeps:S81：计算机控制电源/测量单元向功率型LED输出合适的工作电流，使得功率型LED能点亮但是不产生明显的热效应；利用温度控制单元控制加热冷却单元产生不同的温度值；利用电源/测量单元测量不同温度下电功率P_d；同时利用光学参数测试单元测得光学参数P_O，计算得到光参数-电功率效率E与结温T_j的关系曲线E-T_j；S81: The computer controls the power supply/measurement unit to output a suitable working current to the power LED, so that the power LED can light up but does not produce obvious thermal effects; use the temperature control unit to control the heating and cooling unit to produce different temperature values; use the power supply/measurement The unit measures the electric power P_d at different temperatures; at the same time, the optical parameter P_O is measured by the optical parameter test unit, and the relationship curve ET_j between the optical parameter-electric power efficiency E and the junction temperature T_j is calculated;S82：采用最小二乘原理对E-T_j曲线数据进行线性拟合，得到效率-结温系数k_e；S82: Using the least squares principle to linearly fit the ET_j curve data to obtain the efficiency-junction temperature coefficient k_e ;E＝E_p0[1+k_e(T_j-T₀)] (5)E＝E_p0 [1+k_e (T_j -T₀ )] (5)其中E为光参数-电功率效率，E_p0为环境温度为T₀时的光参数-电功率效率。Among them, E is the optical parameter-electric power efficiency, and E_p0 is the optical parameter-electric power efficiency when the ambient temperature is T₀ .